In an electric motor, a terminal block with a plurality of terminals is used to connect wires connected to a stator winding of each phase and an external power source such as an inverter. Since the terminals need to be insulated from each other, the terminals are generally partitioned by electrically insulating partition plates (hereinafter, insulating plates) made of a resin or the like.
As such a terminal block, JP63-310344A discloses a plastic terminal block integrally molded of an engineering plastic material while including a terminal block and integrally molded with insulating plates for insulating between wires in the terminal block as reinforcement ribs of the terminal box.